Locking strip for panels



Aug. 4, 1964 w. A. SCHROEDER, JR

1.0mm s'rRIP FOR was Filed Sept. 12. 1961 INVENTOR- MZZLQIYIA- c/rmedqi ITTOUEYJ United States Patent 3,143,195 LOCKING STRIP FOR PANELS William A. Schroeder, J12, Bridgeport, Conn. (8 Perry Drive, Monroe, Conn.) Filed Sept. 12, 1961, Ser. No. 137,605 2 Claims. (Cl. 189-36) The present invention relates to an elongate strip that is employed to join together adjacent edges of a pair of angularly disposed panels to interconnect the panels.

The locking strip of the present invention has particular utility when used at the junction of two panels where a corner is to be formed. For example, in a sheet metal duct with one panel forming each side of the duct, the locking strip is used to interconnect the panels where their sides abut. In larger ducts, the panels are usually large and awkward and are required to be installed piece by piece at the site of the duct. Heretofore duct forming panels were either connected as by soldering or other securing methods which generally required that they have a specially formed edge locking configuration. These manners of forming the joints have not been found completely satisfactory in a view of a number of reasons, such as distortion of the panels, inflexibility in on-site work, expensiveness, difliculty to form the joint needing special tools and/or skills, etc.

It is accordingly an object of the present invention to provide a locking strip which facilitates and simplifies the joining of adjacent edges of a pair of angularly disposed panels to form a corner junction and which requires a minimum of labor, skill and tools.

Another object of the present invention is to provide a corner locking strip which requires a minimum of preparation or specially forming of the edges in order to enable the corner locking strip to be employed and which releasably interlocks the edges of the panels.

A further object of the present invention is to provide in a locking strip of the above type for a strip that is economical to fabricate and which, while produced in determinate lengths, may be cut to a shorter length or have strips abutted to form a longer length as determined by the length of the corner joint.

A feature of the present invention resides in the forming of the corner locking strip to have in efiect one L-shaped channel having one end of one leg closed and the other end opened and the forming of the second L-shaped channel having a leg with a closed end and a leg with an open end. The two channels are substantially aligned with the legs extending approximately at the same angle at which it is desired that the panels extend. In the herein disclosed embodiment of the invention, the panels extend out substantially at right angles to each other and hence the channels are shaped to form a right angle corner, though the invention is not to be considered solely limited thereto.

With this construction of a corner locking strip, all that is necessary in order to prepare the adjacent edges of two panels that are to be joined together by the locking strip is to bend each edge to have an end portion that extends transversely to the panel. The two edges of the panels are then placed in their desired position and the locking strip secures the panels together by simply sliding the locking strip therealong after entering the start of the edges of each of the panels into the beginning of the channels.

Other features and advantages will hereinafter appear.

In the drawing:

FIGURE 1 is a perspective including an end of a corner of two panels in which the locking joint of the present invention is used to join the edges of the panels together.

FIG. 2 is an exploded perspective of the parts shown I in FIG. 1.

Fatented Aug. 4, 1964 "Ice FIG. 3 is a perspective of the corner locking strip of the present invention showing the relative position of the strip and the two panels immediately prior to the forming of the corner joint.

FIG. 4 is a cross-section of the locking strip.

Referring to the drawing, FIG. 1, the corner locking strip is generally indicated by the reference numeral 10 and is employed to form a corner between a vertical panel 11 and a horizontal panel 12. The strip 19 and panels 11 and 12 are preferably formed of sheet metal or other rigid yet bendable material. The panel 11 has an end portion 13 that is bent at right angles to the main portion of the panel 11 while the panel 12 similarly has an end portion 14 that extends outwardly at right angles to the panel.

The locking strip 19 of the present invention is formed from a sheet of flat material, such as sheet metal, and is bent to provide a first L-shaped channel 15 having one leg 16 closed as by a reverse bend 17 and having its other leg 13 open as at 19. A second channel 26 is also formed and it has one leg 21 closed by a reverse bend 22 and its other leg, generally indicated by the reference numeral 23, is open.

In use, as shown in FIG. 3, the panels 11 and 12 are disposed perpendicular to each other with the edge 24 of the panel 11 spaced slightly from the edge 25 of the panel 12. It is presently preferred to have the locking strip extend throughout the length of the joined edges. However, if desired, some of the length may be left free of the locking strip. Further, the end portion 13 extends parallel with the panel 12 while the end portion 14- is parallel with the panel 11. The corner locking strip 1t) has its beginning positioned to have the start of the end portion 13 fitting within the other leg 16 of the channel 15 while the start of the panel 11 is positioned in the open leg 18 to extend through and beyond the opening 19. Similarly, the panel 12 has the start of its end portion 14 positioned in the beginning of the closed leg 21 of the channel 20 and the start of the panel 12 is located in the beginning of the open leg 23.

The panels are held stationary in this relative position and by forcing the locking strip 11} to slide longitudinally therealong, the corner locking strip is slid into place to hold the panels together as shown in FIG. 1.

Referring to FIG. 4, it will be seen that the leg 18 of the channel 15 is formed of two portions 26 and 27 while the leg 16 is formed of two portions 28 and 29 interconnected by the reverse bend 17. A corner 3%? between the two portions 26 and 28 and a corner 31 between the portions 27 and 29 place the leg 18 substantially at right angles to the leg 16. The leg 21 of the channel 20 is formed by the portion 27 and another portion 32 interconnected by the re verse bend 22 while the other leg 23 is in effect formed by the portion 29.

It will be appreciated that the channels for receiving the panels 11, 12 and their end portions 13, 14 are made slightly wider than the thickness of the portion of the panel which they receive, in order to facilitate the relative sliding of the panels and the strip. However, to avoid looseness and supply some engagement between the strip and the panels, an end 33 of the portion 32 and an end 34 of the portion 27 are bent slightly inwardly as shown. Each end accordingly has, in effect, a line engagement with its respective panel.

The corner formed by the locking strip of the present invention is relatively strong and rigid because of the shape of the strip, the forming of the end portions 12 and 13, and the manner of their interconnection. The locking strip extends coextensive with the panel edges and if the strip is furnished in fixed lengths, as presently contemplated, it may easily be cut to the length of the panel edges. Moreover, there will be no loss in using the locking strips as left over pieces can be butted together against one another to have the same effect as a continuous strip.

It will accordingly be appreciated that there has been disclosed a corner locking strip for joining together adjacent edges of two panels to form a corner. The locking strip and the panels are easily interconnected simply by placing the panels in their desired position, introducing the edges of the panels into the start of appropriate channels formed in the locking strip and then moving the strip relative to the panels to position the strip coextensively with the edges of the panels.

Variations and modifications may be made Within the scope of the claims and portions of the improvements may be used without others.

I claim:

1. As an article of manufacture, a corner locking strip for joining an edge of one panel with an edge of another panel to form a corner, said edges of the panels each having an angularly disposed flange which extends in a plane parallel with the plane of the other panel when the panels are joined, comprising a unitary strip of substantially rigid material preformed to provide in cross section a first portion, a second portion connected to form an angle with the first portion, a third portion connected to the second a substantially parallel with the plane of the first portion, said first, second, third and fourth portions forming an L- shaped channel to slidably receive endwise the flanged edge of one of said panels, and a fifth portion connected to the fourth portion by a reverse bend to lie in a plane parallel with the fourth portion, the fourth and fifth portions forming a U-shaped channel to slidably receive endwise the flanged edge of the other panel, the first and fourth portions, the second and third portions, and the fourth and fifth portions being respectively substantially parallel and spaced from each other a distance substantially equal to the thickness of the panel parts to be placed therein.

2. The invention as defined in claim 1, in which the free end of the first portion and the free end of the fifth portion are slightly bent towards the fourth portion.

Article entitled: SMACNAS Sheet Metal Duct Manual, published in Heating, Piping and Air Conditioning, No vember 1959.- 

1. AS AN ARTICLE OF MANUFACTURE, A CORNER LOCKING STRIP FOR JOINING AN EDGE OF ONE PANEL WITH AN EDGE OF ANOTHER PANEL TO FORM A CORNER, SAID EDGES OF THE PANELS EACH HAVING AN ANGULARLY DISPOSED FLANGE WHICH EXTENDS IN A PLANE PARALLEL WITH THE PLANE OF THE OTHER PANEL WHEN THE PANELS ARE JOINED, COMPRISING A UNITARY STRIP OF SUBSTANTIALLY RIGID MATERIAL PREFORMED TO PROVIDE IN CROSS SECTION A FIRST PORTION, A SECOND PORTION CONNECTED TO FORM AN ANGLE WITH THE FIRST PORTION, A THIRD PORTION CONNECTED TO THE SECOND PORTION BY A REVERSE BEND, A FOURTH PORTION CONNECTED TO FORM AN ANGLE WITH THE THIRD PORTION AND TO LIE IN A PLANE SUBSTANTIALLY PARALLEL WITH THE PLANE OF THE FIRST PORTION, SAID FIRST, SECOND, THIRD AND FOURTH PORTIONS FORMING AN LSHAPED CHANNEL TO SLIDABLY RECEIVE ENDWISE THE FLANGED EDGE OF ONE OF SAID PANELS, AND A FIFTH PORTION CONNECTED TO THE FOURTH PORTION BY A REVERSE BEND TO LIE IN A PLANE PARALLEL WITH THE FOURTH PORTION, THE FOURTH AND FIFTH PORTIONS FORMING A U-SHAPED CHANNEL TO SLIDABLY RECEIVE ENDWISE THE FLANGED EDGE OF THE OTHER PANEL, THE FIRST AND FOURTH PORTIONS, THE SECOND AND THIRD PORTIONS, AND THE FOURTH AND FIFTH PORTIONS BEING RESPECTIVELY SUBSTANTIALLY PARALLEL AND SPACED FROM EACH OTHER A DISTANCE SUBSTANTIALLY EQUAL TO THE THICKNESS OF THE PANEL PARTS TO BE PLACED THEREIN. 